Coil32
- Coil32 is a free coil inductance calculator, that allows to calculate: single layer and multi layer air core coils, toroidal air core coils, inductors on ferrite rings, in pot core, flat coils on the PCB, and also LC resonance parameters. The program have additional plugins to calculate another kinds of coils.
The application is free for usage and distributing.

Inductor Design Software - RF toroid
- A free too designed to assist in the selection of iron and alloy powder cores.
RF toroid calculate the location of the Self resonate frequencies for series and shunt inductors.